The invention set forth in this specification pertains to new and improved musical instruments. More specifically it pertains to stringed musical instruments which are constructed in such a manner that the necks of such instruments may be adjusted so as to compensate for any neck deformation caused by the tension of the string or strings in such an instrument. The invention also pertains to stringed musical instruments in which two flexible resonators are mounted so as to each receive vibrations through the bridge of the instrument so as to produce a desired tonal effect.
Stringed musical instruments of a wide variety of different types have been commonly employed for many centuries. In spite of the fact that the field of such instruments is extremely old it is considered that there is still a need for improvement in the construction of such instruments. This can be illustrated in several different ways. As such instruments are normally constructed they utilize an instrument body carrying a neck mounted on the body so as to extend from it and one or more strings mounted so as to extend from the end of the neck away from the body generally across the body. These strings are normally used so as to rest upon a bridge mounted on the body in such a manner that as the strings are caused to vibrate the vibrations of the strings will set up sounds which are reinforced in various ways and to various extents by the instrument body.
The tension on the string or strings in such an instrument provides a force component which tends to distort and/or pivot the neck relative to such an instrument body. While this force component is normally not overly significant in instruments employing only a single string it can be quite material in the case of an instrument such as a 12-string guitar employing a plurality of strings under tension. The force component noted will frequently in time cause the neck of an instrument to deform out of an intended or initial shape. This will tend to result in the strings of such an instrument being held in other than a desired manner along the instrument neck and body. This is considered to affect the playability of the instrument and in some cases the character of the tone produced by the instrument.
The latter is considered to be particularly important since it is normally desired that the tone qualities of a musical instrument remain unchanged throughout the life of the instrument. A number of factors affect tone qualities. For reasons which are unimportant to an understanding of the present invention it is often desired to utilize in connection with certain types of music stringed musical instruments of a so-called resonator type. Such instruments are constructed so as to provide mechanical connection between the bridge on the instrument and one or more somewhat flexible, dome-like, somewhat diaphragm-like resonator structures within the body of the instrument which move or resonate in accordance with vibrations of the strings of such an instrument.
Musical instruments employing such structures or resonators have been referred to as resonator-type instruments and as amplifier-type instruments. Instruments of this type have been constructed under the trademark "DOBRO" and are commonly utilized in playing a style of music referred to as "blue grass". Such resonator stringed instruments have, however, been utilized in connection with other types of music. Most generally, these resonator-type musical instruments have taken the form of guitars, although the type of construction employed with them has been employed in other stringed instruments such as violins.